Studies of aggressive behavior in animals and humans have implicated altered metabolism of serotonin, and to a lesser degrees dopamine and noradrenaline. Because MAOA (Monoamine Oxidase A) and MAOB (Monoamine Oxidase B) are known to metabolize serotonin, dopamine; and noradrenaline, the study will evaluate patients for MAO deficiency. Previous studies suggest that genetic defects in the metabolism of these neurotransmitters may affect aggressive behaviors; but such mutation have not been reported.